1. Technical Field
Illustrative embodiments described in this patent specification generally relate to an image forming apparatus, and more particularly to an image forming apparatus including an image forming unit employing one or both of an inkjet recording system and an electrophotographic system and at least upper and lower sheet roll supporters to support rolls of recording media sheets.
2. Description of the Related Art
An image forming apparatus is known that includes an image forming unit that forms images on a recording medium such as a sheet of paper and at least upper and lower sheet roll supporters provided one above the other to respectively support sheet rolls constituted as one long continuous sheet wound around a core. The image forming unit and the upper and lower sheet roll supporters are provided, in that order, from the top to the bottom of the image forming apparatus, and each of the upper and lower sheet roll supporters supports the sheet roll such that the sheet is fed from the sheet roll. Examples of image forming apparatuses using the sheet roll to form images on the sheet fed from the sheet roll include large-scale copiers, printers, plotters, inkjet recording devices, and so forth, which are mainly used for drawing figures.
These image forming apparatuses make use of a sheet feeder. One example of a sheet feeder included in the above-described image forming apparatus has upper and lower pull-out-type sheet roll trays provided one above the other, which are pulled out from a main body of the image forming apparatus to set a sheet roll therein or to fix a sheet jam.
Another example of a sheet feeder includes a sheet roll container for replacing a sheet roll, a sheet puller that unwinds the sheet roll contained in the sheet roll container, a cutter that cuts the sheet unwound by the sheet puller, a sheet conveyance unit to convey the sheet cut by the cutter to a predetermined conveyance path, and a pull-out-type housing including the sheet roll container, the sheet puller, the cutter, and the sheet conveyance unit. A concave sheet roll support member is provided in an upper portion of the housing so that the sheet roll can be temporarily placed on the sheet roll support member when the housing is pulled out from the image forming apparatus.
In yet another approach, a roll feeder detachably attachable to the image forming apparatus includes a supporter provided in a lower portion of the image forming apparatus to support a roll of a recording medium.
The sheet feeder or the roll feeder is generally provided on a front side at the bottom of the image forming apparatus so that a user can easily supply sheets or fix sheet jams from the front side of the image forming apparatus. Such a configuration is called a front operation system or a front loading system, and reduces a height of the image forming apparatus as a result. Accordingly, for example, the user can easily access an operation panel or a document stand provided on the front side at the top of the image forming apparatus, thereby providing a user-friendly configuration.
Although depending on the type, width, and length of the sheet wound around the core, a weight of the sheet roll often exceeds 10 kg. Consequently, it is not easy to set such a heavy sheet roll in the image forming apparatus compared to loading the typically distributed stacks of sheets cut in a predetermined length. Further, because a roll of glossy sheet is usually very costly, more care is needed to set the roll of glossy sheet to prevent damage thereto.
Multiple sheet rolls are often used and stored one above the other in the image forming apparatus, which are typically very wide. The pull-out-type housing described above is used to store the multiple sheet rolls so that the user can easily set the multiple sheet rolls in the image forming apparatus by pulling out the housing from the image forming apparatus and setting the sheet rolls downward in the housing.
However, the pull-out-type housing requires a complex configuration. Specifically, a large number of components are required for the pull-out-type housing, thereby increasing the size of the image forming apparatus as well as production costs. Further, the user has to pull out the housing from the image forming apparatus to set the sheet roll in the image forming apparatus, thereby requiring additional operations by the user.
In order to facilitate setting of the sheet roll and making the image forming apparatus more compact, in one approach an opening through which the sheet roll is set is provided to the image forming apparatus. However, because the sheet roll is set from a horizontal direction through the opening in such an arrangement, it is still difficult for the user to set such heavy sheet rolls in the image forming apparatus. In particular, in a case in which two sheet rolls are set one above the other in the image forming apparatus, the user has to bend down in an uncomfortable position to set the lower sheet roll.
In an effort to overcome the above-described disadvantage, some image forming apparatuses, especially image forming apparatuses in which only one sheet roll is set, have a configuration in which the sheet roll supporter is provided in an upper portion of the image forming apparatuses. However, with the sheet rolls weighing in excess of 10 kg, it is difficult for users in general and female users in particular to lift such loads to the required chest-height level.